video plugin doesn’t work

Hi,
I installed plugins for video (wordpress video plugin is activated, smart video plugin is deactivated) and I included youtube video in my blog but there is nothing, just empty blank space where should be video.
where is the problem?
of course, I use the newest wordpress version and I have the newest Flash version for web browsers. I tried with Firefox and IE and the same case: video is not visible.

and command for video in my post is automatically added by plugin, I used icon which help us to add video: [youtube id=”M1T6QM-A-Cc”]

ooops, solved, command should be without: ID=”
it means better to type by hand than to use icon to add video.